1. Field of the Invention
The present invention relates to a toner container for supplying toner particles to a developer, which is disposed in a copying machine, a printer or the like, as well as to a technique for preventing the leakage of toner particles from a toner outlet of the toner container.
2. Description of the Background Art
In a copying machine, a printer, etc., for example, an electrostatic latent image is created on a surface of a photosensitive drum and a developer apparatus develops the electrostatic latent image so that a toner image is created.
In general, a developer apparatus comprises a developer apparatus main body for supplying toner particles to a photosensitive drum through a developer roller and a toner container for providing the developer apparatus main body with the toner particles. The toner container is detachable from the developer apparatus main body for easy exchange with another toner container, even by ordinary users.
FIG. 15(a) is a perspective appearance view showing an example of a conventional toner container.
A conventional toner container comprises a toner housing portion 901 for internally housing toner particles, a cylindrical member 902, which projects from one side surface of the toner housing portion, and a cylindrical shutter member 903, which is attached for free rotation in the circumferential direction relative to the cylindrical member 902. Internally, the toner housing portion comprises a feeding screw (not shown) for feeding toner particles toward the cylindrical member 902, and a discharge outlet 9021 for discharging to the outside the toner particles fed into the cylindrical member 902 from the toner housing portion 901. (See FIG. 15(b).) The discharge outlet 9021 is disposed approximately in a central lower portion, in the axial direction, of the outer peripheral surface of the cylindrical member 902. An opening portion 904, which is somewhat larger than the discharge outlet 9021, is formed in the shutter member 903, at a position that approximately matches the discharge outlet 9021 in the axial direction.
FIG. 15(b) is a cross sectional view of the cylindrical member 902 and the shutter member 903 of FIG. 15(a), taken along the line X--X. FIG. 15(b) shows a condition in which the shutter member 903 is rotated to position the opening portion 904 facing down. This is a condition in which the position of the discharge outlet 9021 of the cylindrical member 902 and the position of the opening portion 904 of the shutter member 903 match or coincide with each other so that the toner particles fed into the cylindrical member 902 drop and are supplied into the developer apparatus main body from the opening portion 904.
On the other hand, when the toner container is to re-filled, the shutter member 903 is rotated to displace or move the opening portion 904 from the position beneath the discharge outlet 9021 so that the inner peripheral surface of the shutter member 903 can block the discharge outlet 9021. At this stage, to prevent toner particles from leaking out from the opening portion 904, a seal member 905 of a highly compressive elastic material (e.g., foamed urethane) is adhered to the inner peripheral surface of the shutter member 903.
However, when the shutter member 903 is rotated to block the discharge outlet 9021, an end portion 9051 of the seal member 905 is snagged by an edge of the discharge outlet 9021, as shown in FIG. 15(c). Then, if the shutter member 903 is forced to rotate further, the seal member 905 is torn apart or chipped off at that portion, so that a gap is created between the shutter member 903 and the cylindrical member 902 and toner particles leak out from the gap.
A highly compressive member cannot be used in the conventional toner container because of this problem. The conventional toner container has the disadvantage of making it impossible to completely prevent leakage of toner particles during its re-filling.
In most cases involving a small printer and the like, which are in wide use, it is a user who has to replace the toner container in the printer. Hence, even a little leakage of toner particles from a gap between the shutter member 903 and the cylindrical member 902 blacken the user's hands and cloths used to clean the user's hands.